The e-MIM device

We are proud to present our first device, Nephelion’s e-MIM, developed for network developers and field engineers.

The e-MIM is an Ethernet tap powered by a USB 3.0 connection which, in addition to the standard network tap capabilities, has support for packet modification and injection, Power over Ethernet (PoE), and Ethernet bypass. E-MIM stands for Ethernet Man-In-the-Middle, because we think that there should not be any ambiguity about the purpose of this device.

The e-MIM is lightweight, so you can let it hang between two Ethernet cables. The airflow slots on top and the position of the USB cable in the back clearly indicate the direction of network packets when they are being captured or injected.


The e-MIM is the first device of the x-MIM family currently under development, and so is designed to be modular.

One PCB contains the USB connector with its circuitry, the power management function, and the processor itself. It will be common to all the future models.

The second PCB carries all the functions that are specific to the particular medium. For the e-MIM this comprises the Ethernet connectors, and all the plumbing for the PoE pass-through and the Ethernet bypass functions. Future models will support other mediums (w-MIM for WiFi, b-MIM for Bluetooth, u-MIM for USB, etc.) and costs will be kept down by only having to design and manufacture one the PCBs and the two medium-specific end covers.


For simplicity, the e-MIM can be used straight out of the box with Wireshark and a slightly modified version of the libpcap library.

To unleash the power of the e-MIM device, however, users will need Nephelion software, which will enable e-MIM to execute scripts that can monitor, modify, and inject packets in the network. The architecture of the Nephelion software is similar to Linux’s systemtap, and will bring a whole new level of monitoring, analysis, and even real-time patching to the network engineer toolbox. Keep an eye on this site for more articles on this topic.

All the software will be distributed free of charge with our devices and licensed under a copyleft license.

Get a chance to win a second e-MIM

Enter your email address in the form to the left to receive a reminder when the crowdfunding campaign starts. After the campaign is successfully completed, we will draw 10 names from the list of people who both subscribed and pledged and send them a second device free of charge.